Guinness Onion Butter Bottom Round Roast: 5-Ingredient Slow Cooker Dinner Tips, FAQ & printable recipe

Tips for success

For the most flavorful result, choose a well-marbled bottom round roast. The fat renders during cooking and keeps the meat moist.

If you have time, searing the roast in a hot skillet before adding it to the slow cooker adds a nice crust and extra depth, but it's not required—the slow cooker still delivers plenty of flavor. Also, don't be tempted to add extra liquid; the beer and butter provide enough moisture.

To make the sauce even richer, after removing the roast, transfer the cooking liquid to a saucepan and simmer over medium heat for 10–15 minutes to reduce and thicken.

You can also whisk in a slurry of cornstarch and water to thicken it further. Taste and adjust seasoning with salt and pepper before serving. The jus is perfect for spooning over mashed potatoes or for dipping crusty bread.

Variations

• Herb and Garlic: Add 4 cloves of smashed garlic and 2 sprigs of fresh rosemary to the pot along with the onions. The garlic will melt into the sauce, and the rosemary adds an earthy, piney note that pairs well with the stout.
• Mushroom and Thyme: Replace half the pearl onions with 8 oz of cremini mushrooms, halved. Add 2 sprigs of fresh thyme. The mushrooms will soak up the buttery beer sauce and add an umami depth.
• Spicy Stout: Use a spicy stout or add 1 teaspoon of smoked paprika and 1/2 teaspoon of cayenne pepper to the pot before cooking. This gives the roast a subtle heat that balances the richness.
• Non-Alcoholic: Substitute the Guinness with 1 1/2 cups of beef broth and 1 tablespoon of balsamic vinegar. The vinegar adds a touch of acidity and depth that mimics the stout's complexity.

Storage and make-ahead

Fridge

Store leftover roast in an airtight container in the refrigerator for up to 4 days. The meat will stay moist when stored in its sauce.

Freezer

The cooked roast can be frozen in an airtight container for up to 3 months. Thaw overnight in the refrigerator before reheating.

Reheat

Reheat gently in a saucepan over low heat, adding a splash of beef broth or water to loosen the sauce.

Leftover roast can be stored in an airtight container in the refrigerator for up to 4 days. The meat will keep well in the sauce, which helps maintain moisture. To reheat, gently warm in a saucepan over low heat, adding a splash of beef broth or water if needed to loosen the sauce. The flavor actually improves the next day as the spices meld.

This recipe is ideal for meal prep. You can assemble the raw ingredients in the slow cooker insert the night before and refrigerate overnight. In the morning, place the insert in the slow cooker and cook on low as directed.

You can also cook the roast a day ahead, then refrigerate it in the sauce. The next day, skim off any solidified fat, reheat gently, and serve. This makes it perfect for busy weeknights or entertaining.

Serving ideas

Serve this Guinness onion butter roast over a bed of creamy mashed potatoes, which will soak up the rich jus beautifully. The buttery sauce also pairs well with egg noodles or polenta.

For a lighter option, serve alongside roasted vegetables like carrots or green beans, or with a simple green salad to cut the richness. A loaf of crusty bread is essential for sopping up every last drop of the sauce.

For a complete Irish-inspired meal, add a side of colcannon—mashed potatoes with cabbage or kale—or soda bread. The roast also makes a fantastic sandwich filling: pile the shredded beef onto toasted buns and top with the onions and a spoonful of jus. However you serve it, this dish is comforting, hearty, and sure to become a cold-weather favorite.

Frequently asked questions

Recipe card

Guinness Onion Butter Bottom Round Roast: 5-Ingredient Slow Cooker Dinner

Prep 10 minCook 8 hRest 10 minTotal 8 h 20 minServes 6

Ingredients

• 3 1/2 lb beef bottom round roast
• 1 lb pearl onions, peeled
• 1 bottle (11.2 oz) Guinness draught stout
• 1/2 cup (1 stick) salted butter

Instructions

1. Place the beef bottom round roast in the center of a 6-quart slow cooker. Scatter the peeled pearl onions around the roast, tucking some underneath for even cooking.
2. Pour the Guinness stout over the roast and onions. Place the whole stick of salted butter on top of the roast, right in the center.
3. Cover the slow cooker and cook on LOW for 8 hours, or until the beef is fork-tender and easily pulls apart. The internal temperature should reach at least 145°F (63°C) for medium-rare, but for this braise, cook until the meat shreds easily. Let it rest for 3 minutes before slicing.
4. Turn off the slow cooker and let the roast rest in the liquid for 10 minutes. This allows the juices to redistribute and the meat to become even more tender.
5. Using two forks, shred the roast into large chunks, mixing it with the onions and pan juices. Serve over mashed potatoes or with crusty bread, spooning the buttery jus over the top.

Contains: gluten, milk

Estimated nutrition per serving

Calories

520

Protein

35 g

Carbohydrates

12 g

Fat

36 g

Automatic estimate from the ingredient list, not laboratory-verified.